Sinocymatophlebiella hasticercus, Li, Yongjun, Nel, André, Ren, Dong & Pang, Hong, 2011

Li, Yongjun, Nel, André, Ren, Dong & Pang, Hong, 2011, A new genus and species of hawker dragonfly of uncertain affinities from the Middle Jurassic of China (Odonata: Aeshnoptera), Zootaxa 2927, pp. 57-62 : 58-61

Sinocymatophlebiella hasticercus sp. nov.

( Figs 1 –4)

Etymology. Named after Latin prefix ‘hasti-’ and cerci, for our specimen has very strange hastate cerci.

Type locality and horizon. Jiulongshan Formation, Middle Jurassic; near Daohugou Village, Wuhua Township, Ningcheng County, Inner Mongolia, China

Diagnosis. As for the genus.

Description. Forewing hyaline, preserved wing length 45.1 mm, 10.3 mm wide; distance between base and arculus 5.3 mm, between arculus and nodus circa 17.8 mm; distance from nodus to wing apex circa 20.0 mm; distance between Ax1 and Ax2 5.2 mm, between Ax1 and wing base 3.6 mm; five preserved secondary antenodal cross-veins, three of them being between Ax1 and Ax2; Ax2 lies at level of distal third of discoidal triangle; arculus straight; pterostigma and postnodal area not preserved; median space free; submedian space only traversed by CuP-crossing; PsA weakly zigzagged; hypertriangle free; discoidal triangle elongated, divided into three cells; MAb straight, 4.3 mm long; a well-defined three-celled subdiscoidal triangle; base of IR2 circa 3.7 mm basal of nodus; that of RP 3/4 circa 6.0 mm basal of nodus; RP 3/4 and MA parallel and distinctly undulated, with one row of cells between them basally and five rows of cells distally at their preserved length; MA and MP are more or less parallel, postdiscoidal area weakly widened at level of nodus; no Mspl; MP and CuA basally parallel with one row of rectangular cells between them, distally divergent; CuA with eight posterior branches, cubito-anal area with six rows of cells between CuA and posterior wing margin; two rows of cells in anal area; a very short subdiscoidal veinlet, 0.2 mm long.

Hind wing hyaline, pterostigma dark brown; wing 42.6 mm long, 14.1 mm wide; distance between base and arculus 4.8 mm, between arculus and nodus 14.0 mm; distance from nodus to mid of pterostigma 16.6 mm; distance between Ax1 and Ax2 5.5 mm, between Ax1 and wing base 3.7 mm; six secondary antenodal cross-veins, two of them being between Ax1 and Ax2; Ax2 lies opposite distal angle of discoidal triangle; arculus straight; pterostigma elongated, 3.8 mm long and 0.7 mm wide, covering two cells, not basally recessed; pterostigmal brace slightly oblique and aligned with basal side of pterostigma; eight postnodal cross-veins not aligned with postsubnodal cross-veins; median space free of cross-veins; submedian space only traversed by CuP-crossing; PsA straight; hypertriangle free; discoidal triangle elongated, divided into two cells; MAb straight, about 4.5 mm long; a welldefined two-celled subdiscoidal triangle; base of IR2 3.5 mm basal of nodus; that of RP 3/4 5.1 mm basal of nodus; only one cross-vein between RP and IR2 basal of first ‘O’, and this cross-vein is Bqs; two oblique veins ‘O’, about 1.7 mm and 6.1 mm distal of subnodus, second ‘O’ much more oblique than first one; pseudo-IR1 short, 1.7 mm distal of pterostigma; area between RP 1 and RP 2 rather narrow with one rows of cells between them in basal part; base of RP 2 well aligned with subnodus, RP 2 smoothly undulate at its mid part; IR2 weakly undulate, area between it and RP 2 widened at their undulate parts; IR2 and RP 2 basally parallel, with only one row of cells and three to six rows distally; a not very well-developed and zigzagged Rspl with one row of cells between it and IR2; no strongly convex oblique and undulating secondary vein anastomosing between IR2 and RP 3/4 directly basal of origin of Rspl; RP 3/4 and MA parallel and strongly undulate, with one row of cells between them basally and four rows distally; MA and MP more or less parallel, postdiscoidal area weakly widened at level of nodus; no Mspl; area between MP and CuA with one row of cells basally and distally divergent; CuAa with seven well-defined and parallel posterior branches; CuAb directed towards posterior wing margin, anal loops nearly absent, posteriorly completely opened, gaff (basal part of CuA) short, 0.6 mm long; two posterior branches of AA between distal side of anal triangle and CuAb; a distinct anal angle and a three-celled anal triangle (male specimen); a long and broad, strongly sclerotized membranule.

Body: total body length (from head up to end of abdomen, including anal appendages) 83.6 mm. Head 5.8 mm long, 6.2 mm wide, with compound eyes large, medially contiguous; thorax 6.6 mm wide with weak traces of coloration; fore legs partly preserved, tibia about 6.3 mm long, tarsi not visible, femur about 5.7 mm long; abdomen 57.5 mm long, the most wide area 5.2 mm; first abdominal segment 2.2 mm long, second 12.1 mm long, third 7.4 mm long; second segment distinctly constricted with a width of 2.0 mm, no auricles visible on second segment ( Fig. 3); no pair of symmetrical expanded and rounded lobes on abdominal segments III or IV; cerci clearly visible, narrow, 6.1 mm long and about 1.0 mm wide, with strong apical and outer spines and a pronounced dark line suggesting the presence of a longitudinal crest (Fig. 4); inferior appendage (epiproct) very small (about 0.5 mm long), hardly visible.

Figures

FIGURE 1. (a) Photograph of Sinocymatophlebiella hasticercus gen. et sp. nov. CNU-ODO-NN 2010004 - 1, part. Scale bar represents 10 mm. (b) Photograph of Sinocymatophlebiella hasticercus gen. et sp. nov. under alcohol. CNU-ODO- NN 2010004 - 2, counterpart. Scale bar represents 10 mm.